Bottom dump apparatus with sloping discharge walls



April 6,1'1937. H. w. SANFORD BOTTOM DUMP APPARATUS WITH sLoPING DISCHARGE wALLs Filed March 1.1, 19255 3 Sheets-Sheet l Ap s, 1937. H. w. SANFORD 2,076,005

PPARATUS WITH SLOPINCT DISCHARGE WALLS BOTTOM DUMP A Filed March 11, 1935 3 Sheets-Sheet 2 .HWLWSaVoI-w, 0l

PY] 6 1937- H. w. SANFORD 2,076,005

BOTTOM DUMP APPARATUS WITH SLOPING DISCHARGE WALLS Filed March ll, 1935 3 Sheets-Sheet -3 Patented Apr. 6, 1937 UNITED STATES PATET orrlcE BOTTOM DUlVIP APPARATUS WITH SLOPING DISCHARGE WALLS 7 Claims.

This invention relates to improvements in apparatus comprising a hopper having sloping discharge walls for directing the contents of the hopper to a bottom discharge opening, of the type commonly known as a bottom dump apparatus.

Such sloping walls have heretofore been made of many materials, selected either by reason of their cost and availability, easy placement, or

resistance to damage by the impact of the contents thereon during lling of the hopper or erosion by the contents during the discharge.

In attempting to construct hoppers of maximum capacity for a minimum height, it is desirable to have the sloping walls disposed at a low angle to the horizontal. With many materials to be stored in the hopper, this angle must be in excess of 40 degrees, or the material becomes hung and refuses to dischar-ge freely without the employment of an agitating device of some type.

In certain work with bottom dump mining cars, for example, employed for hauling coal from the mine to a dump at the mine head,

it has been customary to employ boiler plate steel for constructing the car members, and with a certain size of lump coal, for example, lumps will slide on such commercial steel plate at an angle of 26 degrees when new, and when rusty at about an angle of 30 degrees. It is customary to make the sloping car walls at an angle of l0 degrees to insure a definite discharge. It will be understood that any deformation of the sloping wall by the impact of coal chunks thereon,

or by scratching, causes an increase of this angle; and that smaller coa-ls usually require a higher angle than larger lumps. From another point of view, this angle may be referred to as the angle of repose since it is the maximum angle at which a material will remain at rest on a sloping Wall.

According to the present invention, such a sloping wall is made with a material-receiving surface of chrome nickel steel plate, either polished or unpolished` and it is then found that the wall is more resistant against denting by impact, owing to the character of the plate employed, is more resistant against scratches, does not lose its polished surface if such be provided,

and above all permits the employment of a lesser parent that the degree of polish is not the critical factor.

Furthermore, according to the present invention, it is possible to cause the lading to slide along a surface at the angle of repose, by giving the material an initial impetus from the upper edge of this low-angle slopin-g surface by providing thereat a llet for producing by elasticity a component of force parallel to the surface, or by providing movable structures for causing such a component of force.

Illustrative examples of practicing the invention are set forth on the accompanying drawings in conjunction with the construction of a bottom dump mining car, but it will be understood that the invention is not limited thereto, as it is applicable generally to any case where a sloping discharge Wall is provided for materials of the character of mined coal.

In the drawings:

Figure 1 is a transverse vertical section through` a coal mining car, indicating the slope of the Walls.

Figure 2 is a detail View, on a larger scale, showing the employment of a stiffening base and a thin non-corrosive chrome nickel lining held in position by side members.

Figure 3 is a View similar to that of Figure 2, showing the employment of a stilening base and a thin lining held in position by spot- Weldin-g.

Figure 4 is a longitudinal upright sectional View conventionally showing a hopper bottom car with one of the walls located at a low angle of slope, with a larger llet than that shown in Figure 1.

Figure 5 is a similar fragmentary section showing the use of a mechanical device, gravitationally actuated, for producing a component of force in a direction parallel to the discharge Wall during discharge.

Figure 6 is a further modication corresponding to Figure 5, but showing resilient means producing the component of force.

Figure 7 is a similar view showing a further modication of structure.

In Figure l, the car is shown to have the Vertical side walls I9, the sloping discharge walls II, the vertical central Walls I2 shown in the usual manner as located inside the car wheels and hence between the rails, and wheels I3. The wheels I3 are connected by axles I4 extending across the car body, which is closed at its bottom by drop bottom doors I5. In general, this type of car is thefsame as that shown in Figure 2 in my U. S. Letters Patent No. 1,268,390. 'I'he sloping discharge walls II are shown at an angle of approximately 20 degrees, which is adequate in practice for the free discharge of coal therefrom as the vehicle passes over a dumping point in the manner described in the aforesaid patent. The sloping walls are constructed of chrome nickel steel plate containing, in the specimens employed, 13% of chromium and 5% of nickel, and being a standard alloy of this relative proportion: although it is obvious that other compositions can be employed which provide a surface formed by a chromium-containing material, and hence not easily subject to abrasion nor to corrosion, and having the characteristic of a low angle of repose. the side wall ||l and the adjacent sloping wall are formed from the same plate with a curved fillet at the angle, but obviously this is not essential to the invention.

In Figure 2, the side wall and sloping wall are of separate elements, the side wall 20 and the base or backing plate 2| of the sloping wall are each formed of commercial steel plate. A sloping wall plate 2| only has a thin veneer or lining 2|@` of chrome nickel steel plate, preferably highly polished. This lining is illustrated as held in position by the provision of rebent ends: the lower end is folded around the lower edge of the commercial steel backing plate 2|, and this backing plate is held to the side sill l2 by rivets 23; the upper end of the lining 2 la is held between an upturned edge of the backing plate 2| and the lower edge of the side wall 20 by rivets 23.

In the form of Figure 3, the side wall and sloping wall are formed with a commercial steel plate backing 36, 5| formed as a single sheet, and covered on the surface exposed to the lading material by a thin veneer 32 of the aforesaid character. This veneer is held fixedly in position against even local movements or distortions by locally spot-welding at suitably selected and spaced points 33.

It is preferred to employ the chrome nickel plate in a highly polished condition, as in such event the angle of repose may be as low as 12 degrees and even less: but it is found, as pointed out above, that even the relatively unpolished commercial plate of this composition has a much lower angle of repose than the ordinary commercial steel.

In the form of construction shown in Figure 4, the arrangement is applied to a larger car, such as a standard railroad hopper car of 55 tons or 1880 cubic feet capacity. The end wall 40 may be of commercial steel plate, while a bottom wall 4| is of chrome nickel steel plate having a fillet 42 of large radius joining it to the wall 45. The bottom wall 4| is illustrated as located at an angle of 16 degrees to the horizontal, which has been found ample for most lading materials. The lower portion 43 of this wall, lading to the hopper door 44 is arranged at a greater angle, while another bottom sheet 45 adjacent the center of the car is likewise illustrated as of chrome nickel steel arranged at an angle of 16 degrees. The vehicle is shown conventionally as having a side wall 46, wheels I5, a truck i3d connecting the wheels, and truck and car bolsters 45 connected to the side sills 41. In operation, when the hopper door 44 is opened, the lading immediately thereon begins to discharge, and ultimately the portion of the lading adjacent the end sheet 4i] is free from a certain portion of the lateral pressure previously existing thereon, and then operates by its weight as applied against the fillet 42 to start the material into sliding motion along the bottom sheet 4|. It is found that this employment of the fillets as shown in Figures 1 to 4, prevents the hanging of material at the junction of the In the particular form shown,

vertical wall |0, 25, 30 or 40 and the bottom wall surface 2|a, 4|, etc.

It is possible, also, to extend the invention further and obtain a yet greater capacity in the hopper, which is of especial value in vehicles, by providing mechanical means by which the bottom wall may when loaded be at an angle less than gain of around 273 cubic feet can be made in the carrying capacity, or l5 percent.

In Figures 5, 6, and 7 such arrangements are shown.

In Figure 5, a conventional showing of a hopper bottom car construction is given with respect to the discharge door 43 leading to the discharge door as in Figure 4, along with an end wall 40 and side wall 45.

The floor or bottom is provided in this construction, however, by a plate 5| mounted by a hinge 52 and joined by a further hinge 53 to an extension plate 54. The weight of the plates 5| and 54 is over-balanced by a counterweight 55 which is connected by a chain ,s

55 passing over a guide pulley 5l, with the plate h 5|. The position of the parts when empty is shown by full lines. When the structure is loaded, the plate 4| is depressed by the load into the position shown by dotted lines, then operating to raise the counterweight 55, while the extension plate 54 folds downwardly and prevents the lading from escaping. At discharge, as the material slides past the opened hopper door, the weight superimposed upon the plate 5| ultimately is insufcient to prevent the plate 5| being raised by counterweight 55, and thereafter the plate 5| moves upwardly toward (and preferably past) the angle of repose. The extension plate 5| affects a horizontal eifort which tends to start the material moving along the surface of plate 5|, so that there is an ample and adequate discharge thereof. The gain, in a standard car of 1880 cubic feet, by this arrangement is about 273 cubic feet. the plate 5| constituting the bottom Wall is limited by stop means 5U.

In Figure 6, the bottom plate 5| is held in its upper, full line position by a spring 55s corresponding in function to the weight 55 of Figure 5. This spring has its upper end received in a cup 58 secured to plate 5|, and its lower end secured in a cup 59 supported by the truck and side sill structures. The operation is essentially the same as before.

In Figure '7, the plate 5| is mounted by a hinge 52 as before and is provided with a cup 48 for the reaction spring 55s. The hinged end plate 54a is mounted by a hinge 53a at the lower edge of the end wall 45. As weight is placed upon the plate 4i, it is forced downward into the dotted line position, the lading also operating upon plate 54a to move it likewise into the dotted line position. It is possible with this arrangement to have the plate 5| extend beyond the end wall 45 when the hopper is loaded, by providing an opening 46a, below the end wall 45; this opening 45a being closed vby the plate 54a while the latter is in the dotted line position. During dis The upward rocking movement of charge, the action of the spring 55s, with assistance upon the plate 54a if the relative angle between plates 5I and 54a is great, causes a movement of the p-lates toward the full line position. 5 During the course of this movement, the plate 54a exerts a force upon the lading which tends to move it along the surface of plate 5|, and the gravitational effect of the lading itself along the sloping surface of plate 54a has a like result. l Ihe stop means 60 here operates to prevent the bottom wall plate from rocking the end plate Ma to such an extent that a gap is formed at the lower edge of the end plate 54a, which might result in the collection of fine particles of mate- 15 rial thereunder: and also it will be noted from Fig. 7 that the stop means 60 operates when the plates 5l and 54a are plane sheets, to prevent these sheets attaining a condition of parallelism, so that the end plate 54a, not only operates to 20 deliver force on the lading for moving it along the surface of plate 5I, but also the sliding of material along the end plate Ella tends to accelerate the movement along the plate 5l.

A fundamental feature of the present invention 25 is the practical application of the discovery of an unexpected property of materials of the character mentioned, in that they present a low angle of repose for the substances referred to, and hence permit the construction of a car of greater capacity for a given width and height in respect to the permitted over-all body dimensions, this angle being much less than the normal angles provided in such structures for free discharge of the lading without any agitation during dis- U'f charge.

Another fundamental feature of the present invention is the increasing capacity of the cars by providing movable members which constitute bottom walls when loaded and which operate as 40 sloping discharge or ilare walls during discharge, and likewisepermit the construction of a car of greater capacity with respect to the permitted over-all body dimensions.

It is obvious that the invention is not limited 45 to the specic forms of embodiment shown, but that it may be employed in many ways within the scope of the appended claims.

I claim:

1. A self-clearing dump apparatus having a 50 sloping discharge wall with a surface of smooth chrome nickel Steel characterized by its resistance to corrosion and abrasion and its low friction opposed to sliding of material in the apparatus, said surface being positioned at an angle not greater 55 than 16 degrees relative to the horizontal when in condition for dumping, whereby lading in the said apparatus may slide along said wall for gravity discharge.

2. A self-clearing coal mining car having a 60 sloping discharge wall with a surface of smooth chrome nickel steel characterized by its resistance to corrosion and abrasion and its low friction opposed to sliding of material in the apparatus, said surface being positioned at an angle not greater 65 than 16 degrees relative to the horizontal when in condition for dumping, whereby lading in the said apparatus may slide along said wall for gravity discharge.

3. A self-clearing dump apparatus having a 70 sloping discharge wall comprised of a rigid backing of commercial steel and a veneer of chrome nickel steel secured to the backingby local spot welds spaced throughout the area of the wall, said' veneer presenting a surface characterized by its resistance to corrosion and abrasion and its low friction opposed tosliding of material in the apparatus, said discharge wall presenting said surface at an angle not greater than 16 degrees to the horizontal.

4. A self-clearing bottom dump apparatus having a sloping bottom discharge wall with a smooth surface of chrome nickel steel characterized by its resistance to corrosion and abrasion and its low friction opposed to sliding of material in the apparatus, said surface being positioned at an angle between 12 and 16 degrees to the horizontal, and a substantially upright side wall joined to the bottom wall by a fillet providing a curved transition surface, the pressure of lading adjacent the side wall being transmitted along the transition surface to cause a movement of the lading along the bottom wall during discharge and thereby clear the apparatus by gravity discharge.

5. A self-clearing bottom dump apparatus having a hopper including a bottom wall pivoted adjacent the discharge point and maintained when the hopper is full and by the weight of superposed lading thereon in a position below the angle of repose of the lading, means constantly operative upon the bottom wall for urging it toward a rocked position above the angle of repose of the lading and being counteracted by the weight of the lading when the hopper is loaded and operating upon discharge of a part of the lading to rock the bottom wall upward with the remaining superposed lading thereon whereby to effect the discharge of the remaining lading located above the bottom wall, and a plate pivoted adjacent its upper edge and resting at its lower edge upon the bottom wall at a point horizontally spaced from the vertical plane of the plate pivot so that the urging means will cause the bottom wall to rock upward and move the plate about its pivot and therewith deliver a force against the lading adjacent the surface of the bottom wall to propel the same toward the discharge opening.

6. A dump apparatus as in claim 5, including stop means for limiting the rocking movements of the bottom wall and effective for preventing an upward rocking movement thereof beyond the positions in which the lower edge of the plate is engaged with the bottom wall.

7. A self-clearing bottom dump coal car having a hopper including a bottom Wall pivoted adjacent the discharge point and maintained when the hopper is full and by the weight of superposed lading thereon in a position below the angle of repose of the lading, means constantly operative upon the bottom wall for urging it toward a rocked position above the angle of repose of the lading and being counteracted by the weight of the lading when the hopper is loaded and operating upon discharge of a part of the lading to rock the bottom wall upward with the remaining superposed lading thereon whereby to effect a discharge of the remaining lading located above the bottom wall, and stop means for limiting the upward rocking movement of said bottom wall at an angle not exceeding 16 degrees to the horizontal, said bottom wall having a surface of smooth chrome nickel steel characterized by its resistance to corrosion and abrasion and its low friction opposed to sliding of material in the apparatus.

HUGH W. SANFORD. 

